Garden Entomology - Royal Entomological Society

Order : Dermaptera
EARWIGS
Earwigs are common residents of gardens throughout the year, and are also occasionally found in
SPECIES PROFILE
FACT FILE
houses. They are in the insect order Dermaptera, named after their skin-like wings, which are rarely
seen. Earwigs can be pests of garden flowers, such as dahlias, clematis and chrysanthemums,
eating young leaves and petals in summer, leaving them pock-marked with unsightly holes. They
also attack some fruit trees, where they cause damage to the fruit, allowing the entry of fungal
diseases. However, while they can be a minor garden problem, earwigs also play a beneficial role in
the garden by attacking pests, such as aphids. To remove earwigs, provide shelter in the form of
inverted pots. Pack these loosely with dried grass and place the pots on the top of canes situated
among the plants. The earwigs can be disposed of once caught, making the use of insecticides
unnecessary.
The common earwig Forficula auricularia
• A common myth suggests that
earwigs can crawl through the
ear and lay eggs on the sleeping
victim’s brain. This is untrue, but
while earwigs are creatures of
damp, moist places, it is unlikely
that they creep into ears.
• While the majority of earwig
species are omnivorous, some
species (the Hemimerina) feed
on the shed skin of the giant rat
and others (the Arixenina) feed
on the skin gland secretions of
bats.
• The oldest fossil Dermaptera is
over 200 million years old and
their likely ancestors were alive
about 290 million years ago.
Forficula auricularia is commonly found in houses, where they are a nuisance, rather than a health risk.
Outdoors, they survive the winter by hibernating in nests. The female mates with a male in this nest and
lays a batch of about 50 eggs. The female guards the eggs and the emerged young (known as nymphs).
Females use their formidable cerci (pincers) to defend their eggs and young against attack. The shape
of the cerci can be used to sex male and female Forficula auricularia. Females have cerci which are close
together, whereas males have strongly curved cerci. There are two forms of male common earwig. The
rarer form has much larger cerci. Females prefer to mate with these males, and males with larger cerci
are also more likely to win skirmishes with other males. However, large cerci are not common since
males require both the right genes and a food-rich environment before they can grow them.